Cancelling subprocess - getting proper return code

README.md

Manually (ctrl+c) cancelling

python child.py
Sleeping
.
.
.
.
^CReceived 2 , exiting 10

Cancelling from parent and subprocess.Popen.send_signal

$ python parent.py
Sleeping
.
.
Sending SIGINT to child
Received 2 , exiting 10
Child exited with 10

child.py

# will sleep 10 sec and exit with code 0, unless it receives SIGINT (ctrl+c),
# in that case it exits with code 10
import signal, sys, time

def signal_handler(sig, frame):
    print('Received', sig, ", exiting 10")
    sys.exit(10)

signal.signal(signal.SIGINT, signal_handler)

print("Sleeping ")
for _ in range(10):
    print(".")
    time.sleep(1)

print("Didn't receive signal, exiting 0")
sys.exit(0)

parent.py

import signal, subprocess, sys, time

proc = subprocess.Popen([sys.executable, "child.py"])
time.sleep(2)
print("Sending SIGINT to child")
proc.send_signal(signal.SIGINT)
proc.wait()
print("Child exited with", proc.returncode)